Can I redo some stuff if I get the right compiler? What languages do I need?

No, a compiler wouldn't do you any good. Most of the game (including the actual game-mechanics) are hardcoded. As for most of the actually accessible parts, you only need to know XML and how to use a text-editor in order to modify them.

Use Randomize All until the map is roughly how you want it, and then edit the rest manually. That's a lot less time-consuming than placing everything by hand. There may be some other things you could do to increase efficiency, but I don't know them. I'm not that familiar with the map editor, as I've hardly used it.